Etherscan vs Watchdata

Etherscan's API exposes the same account balances, transactions, contract source, and gas-tracker data shown on the block explorer, addressed to Ethereum mainnet and its testnets through a single query-parameter-based endpoint. Calls against the older V1 endpoint now return a deprecation notice pointing at the documented V2 migration, so new integrations should build against V2 directly. Free-tier keys cover light use, with paid plans unlocking higher rate limits.

WatchData operates hosted JSON-RPC nodes across Ethereum, Polygon, BNB Smart Chain, and other networks, plus higher-level "Powered API" endpoints for token balances, transfer history, and block-timestamp lookups that would otherwise require custom indexing. Every call needs an api_key issued from the dashboard after a free signup, with a 100-million-unit free monthly allowance before paid plans apply. Responses are plain JSON-RPC.